I requested a copy of my building plans from the city and I received them but I want to make sure I am reading them right. It looks like the foundation says the following:

Slab description

It looks to me like it says 30 inches square by 18 inches deep and the rest pertains to the rebar?

Also, in the copy of the plans below you will see that the garage foundation (in orange) is different from the living room (in pink). I have a pink square representing a 3rd car garage the way my house was built. Does that use the pink foundation plan or the orange one?

Foundation Plan


Those notations (I see 3 on the plan...you’ve circled 2 of them) are in reference to specific footings close to the notations.

Yes, it is calling out the size of the footing, depth of the footing and the reinforcing steel and it’s location in the footing. It says, 30” square by 18” deep concrete pad with 3 - #4 bars each way in the bottom of the footing.

BTW, the rebar should not actually be on the bottom, but held 3” above the ground.

Each concrete pad is shown in the plan and the corresponding size and rebar is shown. So, you’ll use the notation circled in orange for the garage and the one circled in pink for the living room...and I don’t see any square pad in the “pink rectangle”.

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  • I believe the footing is represented by the dotted lines that are more or less under each wall. I thought the "foundation" was the concrete fill within the footings, is that correct? So from the part I posted, can you tell how thick the foundation under my living space is? I just want to make sure that if I have to remove the slab under that pink square that I am not removing 18 " of concrete. – german129 Jun 8 '18 at 5:35
  • The thickness of the slab is not noted on the plan. However, you can find it by looking at the details. The details are referenced with the “detail number “ on the top and the “page number “ on the bottom. The detail should show the thickness of the slab, rebar (if any), bolts into the slab, etc. – Lee Sam Jun 8 '18 at 6:04
  • The quality is terrible but I'll see if I can read the details. Thanks for the help. – german129 Jun 8 '18 at 6:24
  • That says 30' square. ' is the notation for FEET, " is the notation for inches... – JRaef Jun 8 '18 at 21:30
  • @J.Raefield 30’ square would be giant...and there’s 3 of them in this house. I think it’s inches. – Lee Sam Jun 8 '18 at 22:06

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